1. Field of the Invention
The present invention relates to an image communication apparatus which has a recording apparatus of an ink jet recording system mounted thereon.
2. Related Background Art
FIG. 27 is a block diagram showing a constitutional embodiment of a conventional facsimile apparatus.
As shown in the figure, the conventional facsimile apparatus with an ink jet recording apparatus mounted thereon comprises a system involving a facsimile unit (containing a CPU, ROM and RAM) and a system involving a printer unit (containing a CPU, ROM and RAM), both systems being connected through a Centronics interface (I/F) provided as a receptacle on the printer side.
Therefore, both systems have many components duplicated, with neither fully exploiting its capabilities, resulting in bad cost performance. Further, a greater area is occupied by electrical parts of the facsimile apparatus, which impedes the miniaturization of the apparatus.
A system configuration of FIG. 27 will be described below.
In FIGS. 27, 21 to 35 show a system on the facsimile side, wherein a CPU 21 comprises a microprocessor, and controls, in accordance with a program stored in a ROM 22, the whole of the facsimile system including a RAM 23, a non-volatile RAM 24, a character generator (CG) 25, a reader 30, a modem unit 31, a network control unit (NCU) 32, a console unit 27, and a display unit 26.
The RAM 23 stores binary image data read by the reader 30 or binary image data to be printed by the printer, coded image data modulated by the modem unit 31 for output to a telephone line 33 via the NCU 32, and coded image data demodulated from analog waveform signal input through the telephone line 33 via the NCU 32 and the modem unit 31. The non-volatile RAM 24 can securely store data to be saved (e.g., abbreviated dial number) even when the electric power is shut off.
The character generator 25 is a ROM storing therein characters of JIS code or ASCII code to generate character data corresponding to a predetermined code, as required, under the control of the CPU 21. This character data is developed into image data for facsimile to be used in the communications or recording.
The reader 30 comprises a DMA controller, an image processing IC, an image sensor, and a CMOS logic IC, to binarize data read by the use of a contact-type image sensor (CS) under the control of the CPU 21, and to send its binarized data successively to the RAM 23.
Note that the set state of an original on the reader 30 can be detected by an original detector using a photosensor provided on the conveying passageway of the original.
The modem unit 31, which comprises G3, G2 modems and a clock generation circuit connected to these modems, modulates coded transmit data stored in the RAM 23, under the control of the CPU 21, for output to the telephone line 33 via the NCU 32.
Also, the modem unit 31 has an analog signal from the telephone line 33 input via the NCU 32, which signal is then demodulated and stored as coded receive data in the RAM 23.
The NCU 32 switches the telephone line 33 to connect to the modem 31 or a telephone set 34 under the control of the CPU 21. Also, the NCU 32 has means for detecting a call signal (CI), and sends an incoming signal to the CPU 21 when the call signal is detected.
The telephone set 34 is one integral with this facsimile apparatus, specifically composed of a handset, a speech network, a dialer, a ten key and a one-touch key. The console unit 27 comprises a key for starting the transmission and receive of image, a mode selection key for specifying the operation mode such as fine, standard, automatic receive at the transmission or receive time, and a ten key or one-touch key for the dialing.
The display unit 26 comprises an LCD module which is a combination of a 7-segment LCD for clock indication, a pictograph LCD for the indication of various modes, and a dot matrix LCD capable of display with 5×7 dots in 16 digits×1 row, and LEDs.
A resolution converter 29 converts binary data as sent from the reader 30 and then stored in the RAM 23, or received raw data as stored in the RAM 23 via the telephone line 33, the NCU 32 and the modem unit 31 and then decoded, from 8 dots/mm to a recording resolution of 360 dpi.
A CODEC unit 28 is a circuit for assisting the CPU 21 in decoding the received coded data, or coding raw data to be transmitted, composed of an RL (run length)/raw data conversion circuit, and a row data/RL conversion circuit.
A Centronics I/F 35 is an interface for passing print data to the printer or detecting the printer status, which corresponds to a Centronics I/F 41 on the printer side.
On the other hand, 36 to 43 is a system on the printer side, wherein a CPU 36, which comprises a microprocessor, controls the whole of the printer system comprising a RAM 38, a character generator (CG) 39, a print controller 42, an H-V converter 43, the Centronics I/F 41, and a display unit 40 in accordance with a program stored in a ROM 37.
The H-V converter 43 operates to prepare data in a main scan direction which extends transversely, for a number of lines equal to the number a of nozzles of an ink jet head, to take out the same number of data a at the same dot position in those lines in a sub-scan direction, and to rearrange them in the order of data to be supplied to the head, to obtain the data to be supplied to the head which is necessary at the time of actual recording.
The Centronics I/F 41 operates to receive data from the Centronics I/F 35 and stores it in the RAM 38, or return the printer status to the FAX or an external host (not shown), upon an instruction from the CPU 36.
The print controller 42 sends out print data H-V converted and then stored in the RAM 38 to the print head of the ink jet printer.
The character generator 39 storing font data therein, develops a font in accordance with a character code from the external host, when a switch circuit 44 changes over to select the external host. The display unit 40 includes an LED for indicating the state of the printer.
FIG. 28 is an explanatory diagram showing the operation of a conventional recording system as above described. Note that MO1 to M06 in the figure each indicate a specific area of memory.
First, at SO1, the recording RL data in MO1 (RAM 23) is converted into raw data by an RL/raw conversion circuit within the CODEC unit 28, and transferred by DMA (direct memory access) to M02 (RAM 23). Next, at S02, the recording raw data is transferred by DMA to the resolution converter 29 to convert the resolution in the main scan direction from 8 dot/mm to 360 dpi.
The converted data is transferred by DMA to M03 (RAM 23). Then, data is overwritten on M03 to append command data to the top and end of data of one line and obtain raster data with command. Then, its data is sent by DMA to the Centronics I/F 35, then via the switch circuit 44 to the Centronics I/F 41, and further sent by DMA to a receive buffer of M04 (RAM 38).
Then, the CPU 36 analyzes a command stored in the receive buffer, recognizes the top and end of line, and transfers image data, with the command removed, to a raster buffer M05 (RAM 38). Then, data of M05 is sent to the H-V converter 43 at S07 for H-V conversion, after which data is sent to a print buffer of M06 (RAM 38). Then, its data is sent by DMA in succession to the print controller 42 for supply to the print head.
However, the above conventional system has the following drawbacks.
1) Since a facsimile system and a printer system are separately provided, there are many duplicate blocks, resulting in bad cost performance as compared as to the attained functions, considered as a whole.
2) With the great scale of circuit, the apparatus becomes large.
3) As the printer system is connected via Centronics I/F, a recording signal on the facsimile side must be converted for transmission into a form conforming to this interface, thus needing an additional block for adapting to Centronics I/F.
4) As the printer system is connected via Centronics I/F, a recording signal on the facsimile side must be converted for transmission into a form conforming to this interface, thus taking more time in recording on the facsimile side.
As another embodiment of such facsimile apparatus, there is provided one constituted as shown in FIG. 29 to effect fast processing, as described, for embodiment, in Japanese Laid-Open Patent Application No. 7-154590.
With such a constitution, however, two CPUs are required for the control of facsimile and that of printer, and for the image memory, at least two buffers are required for the facsimile and the printer, resulting in a large apparatus with higher price. Also, a separate work area is required for each of the CPUs. Further, there is a loss area in each memory which is used for neither the image buffer nor the work area.
Also, this apparatus has the following drawback, because the printer is a shuttle system of ink jet type even if the apparatus is simply realized with one CPU or one memory. That is, since the printer is required to effect complex, fast processing to drive the carriage for ink jet at high speed, it is difficult to receive or decode image data in real time during the operation of printer.
Similarly, it is also difficult to operate the printer at high speed during the receiving or decoding of image data.
Also, in order to detect whether or not received image has been normally recorded, it is conventionally common practice to confirm whether a predetermined mark can be recorded at a predetermined position on the recording sheet, or whether a discharge of the ink can be sensed by discharging the ink at a predetermined position. However, because of very heavy processing loads for recording or receiving, it is difficult to determine whether the recording is normally performed at an appropriate timing during the recording.
Also, in order to determine whether the image has been normally recorded, a method of detection using a photosensor is well known, but it is required to control the timing of turning on a light source to make a detection, after the output of light source became stable, which is complex.
Also, if the light source is lit up, even when it is unnecessary, it is subjected to severe aging deterioration.